Different flagellar architectures enable different motility behaviors.
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Strategies for swimming and turning vary.
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Flagella can push, pull, flick, and swing, roll, or wrap around the cell.
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Polymorphic transformations and hook dynamics enable new flagellar conformations.
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The relevance of the newly discovered behaviors to chemotaxis is still unclear.
Bacteria use a wide variety of flagellar architectures to navigate their environment. While the iconic run-tumble motility strategy of the peritrichously flagellated Escherichia coli has been well studied, recent work has revealed a variety of new motility behaviors that can be achieved with different flagellar architectures, such as single, bundled, or opposing polar flagella. The recent discovery of various flagellar gymnastics such as flicking and flagellar wrapping is increasingly shifting the view from flagella as passive propellers to versatile appendages that can be used in a wide range of conformations. Here, we review recent observations of how flagella shape motility behaviors and summarize the nascent structure-function map linking flagellation and behavior.
